Field of the Invention
The present invention relates to a method for controlling a main chamber and a sub-chamber of a passenger airbag and a passenger airbag system using the same.
Description of Related Art
An airbag is an occupant protection device which prevents an occupant of a vehicle from directly colliding with a hard structure of a vehicle body when a vehicle collision occurs and thus secures the safety of the occupant. As the technology pertaining to airbags is gradually developed from an initial stage in which an airbag is simply deployed in front of an occupant to protect the occupant, various types of airbags, e.g., a roof airbag and a curtain airbag, configured such that airbags can be deployed not only from the front but also from various other directions have been introduced. In addition, techniques for controlling pressure and timing at which each airbag is deployed depending on conditions of a vehicle collision were introduced to more reliably secure the safety of occupants.
An research moving deformable barrier (RMDB) collision test item is one of vehicle collision test items which are recently added. This is to simulate collision conditions including not only frontal or side collision conditions but also conditions which are more similar to those in a real crash situation. For example, the RMDB collision test item may include a collision test in which a vehicle collides with a barrier at a speed of 90 km/h at an angle of about 15° from the front of the vehicle body.
In the case of an airbag control method and system according to a conventional technique, one of the most significant problems caused when an RMDB collision occurs is that the occupant on the passenger seat comes into hard contact with a vehicle body. In detail, in the case where a three-point fixed safety belt is used as the safety belt of the passenger seat, when the occupant on the passenger seat is leaned forward by a collision, only one shoulder of the occupant is fixed in place by the safety belt, and thus the upper body of the occupant is biased in the direction pertaining to the other unfixed shoulder. In this case, the occupant may be displaced out of a range within which a main chamber of the passenger airbag can protect the occupant, and be brought into hard contact with a center fascia of the vehicle rather than being protected by the airbag.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.